I've come up with these instructions to make your life easier.
if you screw up and break things, don't blame me...
(1) get BSD crypt from uunet:bsd-sources/lib/libc/gen/crypt.c
(2) put it in /usr/src/lib/libc/gen/crypt.c
(3) fix line 512 so it says: return(NULL);
(3) edit /usr/src/lib/libc/gen/Makefile.inc so that it includes compiles
crypt.c instead of crypt_dummy.c
(4) cd /usr/src/lib/libc ; make
ar -d /usr/lib/libc.a crypt_dummy.o
ar -r /usr/lib/libc.a crypt.o
(5) add -DDES to the CFLAGS of the makefile for the following utilities
(either by adding -DDES to the CFLAGS line of the Makefile, if
such a line already exists, or adding a line which says
"CFLAGS+=-DDES" near the top of the Makefile).
(MAKE SURE THAT THE ROOT PASSWORD IS SOMETHING THAT WILL ALLOW YOU TO
LOG IN AFTER YOU ENABLE ENCRYPTION. MAKING IT TEMPORARILY BLANK WILL DO,
AS WILL RUNNING THE VARIOUS "make install"s, THEN *IMMEDIATELY* RUNNING
(6) recompile and reinstall those utilities.